Is it possible to mate a 12A to a s5 tii tranny ?

i would guess that the input shaft of the tii tranny is bigger than the 12A one so that would mean you need to use the tii clutch

but then i assume that only the 12A pressure plate can bolt onto the 12A flywheel.

So the question is really

1) does the bolt pattern line up ?
2) will the tii starter still line up with the 12A flywheel
3) can the tii clutch be used with the 12A pressure plate ?

if the answers are yes, no, no then i guess if one really wanted to do this then you would have to bolt the tii flywheel onto the 12A so as to get the starter to line up and get the tii pressure plate and clutch to line up

if the answers are no, no, no......then its a lost cause and this should not be attempted.

 

You have 2 options. 1. Have a 225 mm clutch disk made with center hub to match the TII input shaft. 2. Run a TII lightweight flywheel and counterweight to match your engine and use a TII 240 mm clutch. First options uses the stock starter, 2nd one a TII starter.

Then the shifter housing will need modded to move the shifter back to the stock 1st gen position. That how to is in the archives.

You might e-mail RB and ask them what they have available for parts.

 

Yes, No, No to your questions. The bolt pattern is different between TII and NA starters, so I can't see trochoid's option #1 working without at least some machining of the TII tranny bellhousing. I'd suggest going with option 2. Assuming you are looking for the TII tranny to handle the seriously increased power output of your 12A, then the larger surface area of the TII clutch will be a welcome upgrade as well.

The shifter mods are detailed with pics here:
https://www.rx7club.com/1st-generation-specific-1979-1985-18/tii-tranny-fitment-sa-555938/

Note that you will need a custom driveshaft as well, as the TII tranny output shaft is larger than the NA unit.

 

I know there is a difference between the NA and TII starters, but I seem to remember that some did the NA starter, and flywheel with a TII tranny. He had to enlarge/shift one of the holes in the bell housing for the NA starter to engage. Not entirely sure on the details.